Plural-filament electric bulb



Patented July 19, 1927.

mum-a a. snowman, or reason, urea.

PLURAL-IILAMEN'I- ELECTRIC Bonn.

mama flled Iune 22, 1925. Serial No. 38,700.

This invention relates to electric bulbs and particularly to those provided with plural filaments so that each successive filament may be burnedv following the burning out of the 1, showing the single contact in the central portion of the base. Fig. is a bottom view of the lamp base shown in the construction illustrated in Fig. 2, illustrating the two-contacts on the bottom of the base.

Fig. 6 is a detail perspective view of the ii laments mounted in the lamp illustrated in Referring particularly to Fig. 1, the nu-' 5 first filament.

An object of the invention resides in providing a lamp construction with a plurality of independent filaments connected with independent terminals at one end and to a common terminal at the other end.-

- plication:

' construction. H 7 Fig. 3 is a view similar to Fig. 2- showin A' further object'of the invention resides in providing a lamp construction'having a plurality of independent filaments together with suitable means for successively interposing the filaments in the circuits as they burn out.

The invention further includes the provision of anelectric lamphaving a plural ty I of filaments connected toa'. common terminal the opposite ends of said filaments connected to independent terminals so that they" may be independently placed in circuit, and the rovision of manually operated means for independently interposing said filaments in circuit so its new filament can be interpositioned in-the circuit after the previously.

used filament has burned out.

The invention comprehends other objects and improvements in the details of construction and arrangement of parts which are a more particularly inted out in the following detailed description and in the claims directed to a preferred form of the invention, it being understood however, that various changes in'the desired shape and arrange- "ment of parts may be made without departing from the spirit orscope of the invention as herein set forth. v

In the drawing forming part of this ap- Figure. 1 illustrates in side elevation an improved lamp construction embodying the improvements of the present invention, the

base-of said lampbeing vshown in section.

tion aving the base shown in section which "illustrates the a plication-of the principle "to a certain slig tly different type of lamp theTpplication of the invention to, a stil difierent type oflamfi construction.

,- Fig. 4 is'a-bottom plan view'o f the lamp 1 base of the lamp construction shown in Fig.

pair of filaments 7 and 8 respectively. The

filaments 7 and 8 are each connected at one end of the lead-in wire 4 while the opposite ends are connected to the lead-in wires 5 and 6 which also form the support therefor so that the filaments may be independently interposed in'electric circuits. In the bottom portion ofthe base 2 is mounted a cylindrical sleeve member 9 constructed of'suit- 1 ableinsulating material, in which is mounted ametallic sleeve 10 having-a threaded bore which is in spaced relation with respect to the metallic sleeve 11 also mounted in sleeve 9 and which threadedly mounts the contact screw 12. Access is provided to'the screw 12' through the opening 13 in the base 2.

The common lead-in wire 4 is electrically connected with the central contact 14011 the shell electrode 15 is electrically connected with the metallic sleeve 10 to which the lead-in-wire 5 isconnected. The lead-in wire 6 is electrically connectedto the sleeve "11 and from this construction it will be seen that in the ordinaq filament 7 willbe ated to incandescence use of the lamp the an t e shell electrode 15 in'a suitable electhe screw 12 can be operated sothat it ma tr ic cirfilitf "When thefilament 17 burns gut Fi .2 is an elevation-of the lamp construcbe threaded into the sleeve 10 which w'l inte ,struction can be .provldedto ave a. cubic onstruction illustrated in ose thefilamen't Sintotheelectric -circuit tween the" shell-electrode 15 and contact 14. In this way a sin le lam conlightso that th e construction and operation 05 Fig. 2, the sanie structural relation of the,

parts exists, but in this lamp construction a pair .of contact'terminals as indicated. at 16 and 17 are used to form the circuit connections for the filaments in a suitable ele c-- tric circuit instead of the single contact in shell electrode structure of thefldevice illustrated'in Fig. 1. These two types of lamps are of well known construction in the art and are particularly'used in connection with automobile headlights and the like.

Figure 3 is a similar embodiment of the invention as shown wherein thesame isapplied to the usual screw-lamp 8 as used in connection with lamps constructed for house lighting and other similar urposes. In this constructionthe lamp bill or vacuumized container as illustrated .at ;18 which carries the usual base construction 19 including the screw contact shell-'20 at the central contact point or-electrode Suitable filament supporting wires 22' are mount- I ed on the supper end of the standard 23 forming of the plug of the lamp and support ari'pair of filaments 24 and25 respectively. The supporting wires 22 for the filaments are separated in their central portions so as not to have electrical connections with one another and mounted for support uponone another by the glass balls 26. A common lead-in wire27 extends to one end of both filaments while independent lead-in wires 28 and 29 respectively are connected to the opposite ends'of the filaments 24 and 25 respectively. The-lead-in wire 28, is connected to the shell electrode 20 as illustrated,

while the lead-in wire 29 is electrically con independent lead-in wires are connected to 1 cessively' interposed in circuit in any desired manner for use after other filaments have I burned out.

- What is claimed as new is:v

v 1. A-lamp of the class described, comprising an evacuated container, a base mounted on said container 'hzwinga pair of contact terminals thereon, a sleeve member formed of insulating'material mounted in said base, a plurality of' metallic sleeves mounted in relative spaced-relation within said insulating sleeve, a movable contact member for engaging said metallic sleeves in a predetermined manner, a plurality of filaments supported in said evacuated container, 9; common electrical connection between one of the terminals on said lamp base and one end of each of said filaments, and independent circuit connections between the opposite ends of said filaments and predetermined contact sleeves in said insulating sleeve, whereby theoperation of the movable contact members for engaging predetermined metallic sleeves will operate to interpose predetermined filaments in circuit between the opposite terminals on said lamp base 'ina predetermined manner.

2'. An electric lamp, comprising an evacu-' ated container, a base mounted on said container having a pair of contact terminals thereon, asleeve member formed of insulating material mounted within the base and opening through-one side thereof, a plurality of contact blocksmounted in said insulating." sleeve in s aced relation and having alined openin s ormed therein,'a contact member movab y-mounted in said contact block with- -9 in the sleeve member and-, adapted to make]. and break an electric circuit between said blocks, and a plurality of filaments supported in said evacuated container having; a-.com mon electrical connection with one of said blocks and terminals on said lamp base, hav-.-'. ing the opposite terminals electrically connected to predetermined other blocks in. spacedrelation, said movable contact-memher being adapted to control the electrical connection of the last named terminals, of said filaments with the other contact terminal on the lamp base. In testimony whereof I afiix my signaopposite ends of the filaments and asuitable ture. contact mechanism so that they maybe sucv ELMER R. CLOWARDi 

